[Security Assistant] Fix inference rollover (elastic#214718)

## Summary
Fixes elastic#214709 (comment)

The issue was caused by the rollover of the Knowledge Base Data stream
to use default inference endpoint.
During the rollover it first got to this branch
https://github.com/elastic/kibana/blob/main/x-pack/solutions/security/plugins/elastic_assistant/server/ai_assistant_service/index.ts#L347-L369
where it went through all the steps and continued, but it didn't
override `this.knowledgeBaseStream`, so the next time someone hit API it
was going through this path calling `getInitializedResources` to make
sure all data streams were configured properly, but because we didn't
update `this.knowledgeBaseStream` it was failing, because the original
configuration that was created in service constructor was not called,
that's why it was returning an error

Author: patrykkopycinski

x-pack/platform/packages/shared/kbn-elastic-assistant/impl/knowledge_base/knowledge_base_settings_management/use_knowledge_base_table.tsx

@@ -46,8 +46,8 @@ const useUserProfile = ({ username, enabled = true }: { username: string; enable
     },
     select: (profile) => {
       return {
-        username: profile?.[0].user.username ?? 'Unknown',
-        avatar: profile?.[0].data.avatar,
+        username: profile?.[0]?.user.username ?? username ?? 'Unknown',
+        avatar: profile?.[0]?.data.avatar,
       };
     },
     enabled: !!(enabled && username?.length),

x-pack/solutions/security/plugins/elastic_assistant/server/ai_assistant_data_clients/knowledge_base/create_knowledge_base_entry.ts

@@ -120,7 +120,7 @@ export const transformToUpdateSchema = ({
   const base = {
     id: entry.id,
     updated_at: updatedAt,
-    updated_by: user.profile_uid ?? 'unknown',
+    updated_by: user.profile_uid ?? user.username ?? 'unknown',
     name: entry.name,
     type: entry.type,
     global: entry.global,
@@ -186,9 +186,9 @@ export const transformToCreateSchema = ({
   const base = {
     '@timestamp': createdAt,
     created_at: createdAt,
-    created_by: user.profile_uid ?? 'unknown',
+    created_by: user.profile_uid ?? user.username ?? 'unknown',
     updated_at: createdAt,
-    updated_by: user.profile_uid ?? 'unknown',
+    updated_by: user.profile_uid ?? user.username ?? 'unknown',
     name: entry.name,
     namespace: spaceId,
     type: entry.type,

x-pack/solutions/security/plugins/elastic_assistant/server/ai_assistant_service/index.ts

@@ -224,7 +224,7 @@ export class AIAssistantService {
   private async rolloverDataStream(
     initialInferenceEndpointId: string,
     targetInferenceEndpointId: string
-  ): Promise<void> {
+  ): Promise<DataStreamSpacesAdapter> {
     const esClient = await this.options.elasticsearchClientPromise;
 
     const currentDataStream = this.createDataStream({
@@ -289,6 +289,8 @@ export class AIAssistantService {
     } catch (e) {
       /* empty */
     }
+
+    return newDS;
   }
 
   private async initializeResources(): Promise<InitializationPromise> {
@@ -340,12 +342,12 @@ export class AIAssistantService {
 
       // Used only for testing purposes
       if (this.modelIdOverride && !isUsingDedicatedInferenceEndpoint) {
-        await this.rolloverDataStream(
+        this.knowledgeBaseDataStream = await this.rolloverDataStream(
           ELASTICSEARCH_ELSER_INFERENCE_ID,
           ASSISTANT_ELSER_INFERENCE_ID
         );
       } else if (isUsingDedicatedInferenceEndpoint) {
-        await this.rolloverDataStream(
+        this.knowledgeBaseDataStream = await this.rolloverDataStream(
           ASSISTANT_ELSER_INFERENCE_ID,
           ELASTICSEARCH_ELSER_INFERENCE_ID
         );
@@ -362,7 +364,7 @@ export class AIAssistantService {
             `Deleted existing inference endpoint ${ASSISTANT_ELSER_INFERENCE_ID} for ELSER model '${elserId}'`
           );
         } catch (error) {
-          this.options.logger.error(
+          this.options.logger.debug(
             `Error deleting inference endpoint ${ASSISTANT_ELSER_INFERENCE_ID} for ELSER model '${elserId}':\n${error}`
           );
         }
@@ -385,13 +387,14 @@ export class AIAssistantService {
           },
           writeIndexOnly: true,
         });
-        await this.knowledgeBaseDataStream.install({
-          esClient,
-          logger: this.options.logger,
-          pluginStop$: this.options.pluginStop$,
-        });
       }
 
+      await this.knowledgeBaseDataStream.install({
+        esClient,
+        logger: this.options.logger,
+        pluginStop$: this.options.pluginStop$,
+      });
+
       await this.promptsDataStream.install({
         esClient,
         logger: this.options.logger,

x-pack/solutions/security/plugins/elastic_assistant/server/lib/data_stream/documents_data_writer.ts

@@ -136,13 +136,15 @@ export class DocumentsDataWriter implements DocumentsDataWriter {
               path: 'users',
               query: {
                 bool: {
-                  must: [
-                    {
-                      match: authenticatedUser.profile_uid
-                        ? { 'users.id': authenticatedUser.profile_uid }
-                        : { 'users.name': authenticatedUser.username },
-                    },
+                  should: [
+                    // Match on users.id if profile_uid exists
+                    ...(authenticatedUser.profile_uid
+                      ? [{ term: { 'users.id': authenticatedUser.profile_uid } }]
+                      : []),
+                    // Always try to match on users.name
+                    { term: { 'users.name': authenticatedUser.username } },
                   ],
+                  minimum_should_match: 1,
                 },
               },
             },